JP2000260656A - Method for manufacturing film capacitor and film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the electrical connection area of internal and external electrodes and to increase an allowable pulse current by laminating or winding a dielectric film that has shrunk in a width direction due to heating so that a double-sided metallized film projects toward both sides in the width direction by a specific length after slitting into a specific slit width. SOLUTION: A double-sided metallized film 1 that is slit into a specific width while an electrode is formed on both the surfaces of a wide dielectric film 2 in a stripe shape in the longitudinal direction by deposition, and the wide dielectric film 2 are slit into ±0.2 mm of the slit width of the double-sided metallized film. After that, the dielectric film that has shrunk in a width direction due to heating is laminated or wound so that the double-sided metallized film projects by 0.03 mm or more and 0.4 mm or less at both sides in the width direction of the dielectric film. Also, shrinkage by the heat of the dielectric film due to heating after slitting is within a range of 0.2% or more and 10% or less for the slit width for obtaining stable shrinkage, thus controlling shrinkage dimensions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a film capacitor and a film capacitor.

[0002]

2. Description of the Related Art Conventionally, a method and a structure for manufacturing a capacitor of this type are as shown in FIGS.

In FIG. 3, a metal serving as an internal electrode is formed by vapor deposition on both sides of a wide dielectric film so as to form stripes in the longitudinal direction, and a double-sided metallized wide film 1 is obtained.
This is slit into a predetermined width by the slit blade 5 to obtain a double-sided metallized film. The slit film is obtained as a reel-shaped double-sided metallized film 3 which can be wound and transported in a reel shape. A wide dielectric film is similarly slit by a slit blade so as to be 1 mm to 2 mm narrower than the slit width of the double-sided metallized film to obtain a dielectric film.
The slit film is wound up in a reel shape to obtain a transportable reel-shaped dielectric film.

[0004] Next, in Fig. 4, the reel-shaped double-sided metallized film 3 and the reel-shaped dielectric film 4 are respectively unwound from the reel and passed through a dozen or so rollers, on both sides in the width direction of the dielectric film. The capacitor element body 6 is formed by laminating or winding a predetermined length so that the metallized film protrudes. Next, a heating press is applied to the laminated or wound capacitor body to provide mechanical strength. Next, a molten metal is sprayed on a portion of the capacitor body where the double-sided metallized film protrudes to form an external electrode electrically connected to the internal electrode, thereby obtaining a capacitor.

[0005]

In this method for manufacturing a film capacitor and the film capacitor, the internal electrode formed by vapor deposition and the external electrode formed by spraying molten metal are electrically connected to each other over a wider area. You are required to connect.

If the area of the electrical connection is small, the current concentrates on the narrow electrical connection when charging or discharging the capacitor, and the current exceeds the allowable current of the electrode formed by vapor deposition.
The electrode of the electrical connection is melted. That is, the allowable pulse current of the capacitor becomes small. If the protrusion on both sides in the width direction of the double-sided metallized film is less than 0.03 mm, the electrical connection area between the internal electrode and the external electrode becomes extremely small. Further, when the thickness exceeds 0.4 mm, the protrusions of the adjacent double-sided metallized films via the dielectric film tend to overlap each other, and the molten metal does not enter between the layers, so that the electrical connection area between the internal electrode and the external electrode is narrow. Become. When the protrusion on both sides in the width direction of the double-sided metallized film is 0.03 mm or more and 0.4 mm or less, the electrical connection area between the internal electrode and the external electrode can be maximized.

However, in the conventional technique, since the double-sided metallized film and the dielectric film are unwound from a reel-shaped state, and are laminated or wound through more than a dozen rollers, the double-sided metallized film is formed by meandering. Since the amount of protrusion of the film in the width direction becomes unstable, the amount of protrusion is set to 0.03.
In order to secure the width of not less than 1 mm, the width of the dielectric film must be narrower by 1 mm to 2 mm than the width of the double-sided metallized film. That is, the protrusion amount becomes 0.5 mm or more. As a result, the electrical connection area between the internal electrode and the external electrode is small, and the film capacitor has a small allowable pulse current of the capacitor. Therefore, the amount of protrusion of the double-sided metallized film in the width direction is set to 0.03 mm or more and 0.4 mm or more.
A method for manufacturing a film capacitor and a film capacitor described below are required.

According to the present invention, in a method for manufacturing a film capacitor and a film capacitor, the amount of protrusion of a double-sided metallized film in the width direction can be stably set to 0.03 mm or more,
It is an object of the present invention to obtain a film capacitor having a thickness of 0.4 mm or less, a large electrical connection area between an internal electrode and an external electrode, and a large allowable pulse current.

[0009]

In order to solve this problem, a method of manufacturing a film capacitor and a film capacitor according to the present invention have electrodes formed on both surfaces of a wide dielectric film by vapor deposition in a stripe shape in the longitudinal direction. A double-sided metallized film slit to a predetermined width and a dielectric film shrunk in the width direction by heating after slitting a wide dielectric film within ± 0.2 mm of the slit width of the double-sided metallized film. A double-sided metallized film is laminated or wound so as to project from 0.03 mm to 0.4 mm on both sides in the width direction of the body film. Laminating or winding a double-sided metallized film and a dielectric film without processing it into a reel-shaped double-sided metallized film or a reel-shaped dielectric film, and without passing through more than a dozen rollers after slitting Therefore, the amount of protrusion of the double-sided metallized film in the width direction is stably at least 0.03 mm,
0.4 mm or less, the electrical connection area between the internal electrode and the external electrode can be widened, and a film capacitor with a large allowable pulse current can be obtained.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The invention as set forth in claim 1 of the present invention relates to a double-sided metallized film in which electrodes are formed on both sides of a wide dielectric film by stripping in the longitudinal direction and slit to a predetermined width. After slitting a wide dielectric film to within ± 0.2 mm of the slit width of the double-sided metallized film, the dielectric film shrunk in the width direction by heating is metallized on both sides in the width direction of the dielectric film. The film has a structure that is laminated or wound so that the film protrudes from 0.03 mm or more and 0.4 mm or less, without winding into a reel shape, and without passing through more than a dozen rollers from the slit. Since the double-sided metallized film and the dielectric film are laminated or wound, the amount of protrusion of the double-sided metallized film in the width direction can be stably set to 0.03 mm or more, 0.4 m or more.
m, the electrical connection area between the internal electrode and the external electrode can be increased, and the allowable pulse current can be increased.

According to a second aspect of the present invention, the shrinkage of the dielectric film due to heating after the slit is set to 0.2% or more and 10% or less with respect to the slit width. When the film is laminated or wound, the protrusion amount in the width direction of the double-sided metallized film can be stably set to 0.03 mm or more and 0.4 mm or less, and the electrical connection area between the internal electrode and the external electrode can be widened. This has the effect of increasing the pulse current.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 schematically shows a method of manufacturing a film capacitor according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a double-sided metallized wide film. A conductive layer serving as an internal electrode is formed on both surfaces of a wide dielectric film serving as a dielectric by stripping in a longitudinal direction in a striped manner, and wound into a reel. It was taken. Reference numeral 2 denotes a wide dielectric film, which is formed by winding a film serving as a dielectric into a wide reel. As a film to be a dielectric, polyethylene terephthalate, polypropylene, polyethylene naphthalate, polyphenylene sulfide, or the like can be used without limitation as long as it shrinks by heating. Reference numeral 5 denotes a slit blade, which slits the double-sided metallized film 1 and the wide dielectric film 2 to a predetermined width. In FIG. 1, slitting is performed by a blade, but any method that can slit a wide dielectric film or a double-sided metallized wide film to a predetermined width is not limited to liquid, gas, heat, laser, etc. Can be used. In FIG. 1, the wide dielectric film 2 and the double-sided vapor-deposited wide film 1 are simultaneously slit by the same slit blade 5, but the width of the dielectric film is within ± 0.2 mm of the width of the double-sided metallized film. The method is not limited to a method in which the slits can be separately formed as long as the slits can be slit. Reference numeral 7 denotes a hot roller for heating and shrinking the dielectric film obtained by slitting a wide dielectric film. The protrusion of the double-sided metallized film in the width direction is 0.03 mm or more and 0. The temperature is adjusted to be suitable for shrinking the dielectric film so as to be 0.4 mm or less.
In FIG. 1, the dielectric film is heated by bringing the dielectric film into contact with the hot roller 7. However, if the dielectric film is thermally shrunk to a predetermined width, a method using radiant heat, heating, etc. Contact using air, etc.
It is not limited regardless of non-contact. If the difference between the slit width of the dielectric film and the slit width of the double-sided metallized film exceeds ± 0.2 mm, it becomes extremely difficult to control for thermally shrinking the dielectric film to a predetermined width. More preferably, it is within a range of ± 0.1 mm. Regarding the shrinkage of the dielectric film due to heat due to heating after the slit, stable shrinkage is obtained in the range of 0.2% or more and 10% or less with respect to the slit width, and the shrinkage dimension can be controlled. If it is less than 0.2% or more than 10%, the amount of shrinkage due to heating is unstable, and it becomes difficult to control the shrinkage dimension. Reference numeral 6 denotes a capacitor element, which is formed by slitting a wide dielectric film 2 and then shrinking the film by heating, and a double-sided metallized film obtained by slitting a double-sided metalized wide film 1. On both sides in the width direction of the film, a double-sided metallized film having a thickness of 0.03 mm or more, 0.4
It is obtained by winding so as to protrude by not more than mm. Since the slit is wound without being wound into a reel and without passing through a dozen or more rollers from the slit, the amount of protrusion can be secured stably. If the protrusion on both sides in the width direction of the double-sided metallized film is less than 0.03 mm, the electrical connection area between the internal electrode and the external electrode becomes extremely small. On the other hand, when the thickness exceeds 0.4 mm, the protrusions of the adjacent double-sided metallized films via the dielectric film tend to overlap each other, and the electrical connection area between the internal electrode and the external electrode is reduced. Within the range of 0.03 mm or more and 0.4 mm or less, the electrical connection area between the internal electrode and the external electrode can be increased. More preferably, 0.05 mm or more, 0.2 m
m or less. In addition, in FIG.
Although the capacitor body 6 is obtained, the laminated or wound one may be cut to form a laminated capacitor body. Next, the laminated or wound capacitor body is subjected to a heat press to ensure the mechanical strength of the capacitor body. Next, a molten metal is sprayed on a portion of the capacitor body where the double-sided metallized film protrudes to form external electrodes electrically connected to the internal electrodes, thereby obtaining a film capacitor. In addition,
The film capacitor may be obtained by cutting after forming the external electrode. Note that the heating press may not be performed.

FIG. 2 schematically shows a cross section of a film capacitor according to an embodiment of the present invention. In FIG. 2, reference numeral 8 denotes a double-sided metallized film. Reference numeral 9 denotes an internal electrode obtained by vapor deposition. Reference numeral 10 denotes a dielectric film, which is slit within ± 0.2 mm of the width of the double-sided metallized film and then heated so that the amount of protrusion of the double-sided metallized film in the width direction is 0.
It is obtained by shrinking the dielectric film so that the thickness is not less than 03 mm and not more than 0.4 mm. Reference numeral 11 denotes an external electrode, which is electrically connected to the internal electrode 9 by spraying a molten metal.

[0016]

As described above, according to the present invention, in the method for manufacturing a film capacitor and the film capacitor, the amount of protrusion of the double-sided metallized film in the width direction is stably set to 0.03 mm or more and 0.4 mm or less, It is possible to obtain a film capacitor in which the electrical connection area between the internal electrode and the external electrode is increased and the allowable pulse current is increased.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a method for manufacturing a film capacitor according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a film capacitor according to an embodiment of the present invention.

FIG. 3 is a schematic view of a conventional method for manufacturing a film capacitor.

FIG. 4 is a schematic view of a conventional method for manufacturing a film capacitor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 double-sided metallized wide film 2 wide-dielectric film 3 double-sided metallized film 4 reel-shaped dielectric film 5 slit blade 6 capacitor element 7 hot roller 8 double-sided metallized film 9 internal electrode 10 dielectric film 11 external electrode

Claims (2)

[Claims] 1. A double-sided metallized film in which electrodes are formed on both sides of a wide dielectric film by vapor deposition in the longitudinal direction and stripped to a predetermined width, and a slit of a wide dielectric film is formed by slitting a double-sided metallized film. After slitting within ± 0.2 mm of the width, the dielectric film shrunk in the width direction by heating and the double-sided metallized film protrude from both sides in the width direction of the dielectric film by 0.03 mm or more and 0.4 mm or less. A method for manufacturing a film capacitor having a structure laminated or wound on a film, and a film capacitor. 2. The film capacitor manufacturing method and film capacitor according to claim 1, wherein the shrinkage of the dielectric film due to heating after the slit is 0.2% or more and 10% or less with respect to the slit width.